Cozy Mark IV Chapter 6, Fuselage Assembly


In Chapter 6, the fuselage sides and the bulkheads come together as a center section fuselage. I ran into some problems while working on this chapter and I couldn't quite figure out what I did. To be honest, I was very confused by the middle of this chapter. But, the errant pieces were cut out of the airplane and the work was repeated. The great thing about composite construction is that anything can be repaired. If I were building a metal airplane with holes and rivets, I would be really upset at this point about putting a bulkhead in the wrong place with unnecessary holes all over the place.

Fuselage Assembly involves putting together the bulkheads that were built in Chapter 4 with the fuselage sides built in Chapter 5. The joints are taped with fiberglass strips, and the airplane begins to take shape. The accuracy of this chapter is pretty important, so everything learned in the earlier chapters is pretty important.


The landing gear bulkheads have been added. In this photo the aft landing gear bulkhead is visible, and 8 inches ahead of that is the forward landing gear bulkhead (lower section). At an angle, is the upper section of the forward landing gear bulkhead. This area will soon get a very large buildup of fiberglass once I figure out what layup is required to properly tape this section to the fuselage. I don't want to miss any layups.
Fiberglass layers scheduled for this bulkhead:

After asking the online forums of builders about adding the 2-ply BID tapes (as illustrated below) I was reminded to read the Cozy Builders FAQ maintained by Marc Zeitlin on his Cozy Builders resource site. The funny thing is that I suggest new builders that the first thing that they should do with their plans is to print up this FAQ and annotate their plans. Now that the FAQ has been read, the BID tape is applied and covered with peel ply as you see in the smaller photo.
Cozy Mark IV, landing gear areaCozy Mark IV, landing gear bulkheads, viewed from below during assembly and BID taping
Hot Tip for builders doing Chapter 6: At this point, the plans stop spelling out everything. Read the plans carefully, then read the FAQ to find out what is missing in the plans.


This photo (below) was taken before any glass or epoxy is applied. The fuselage is only held together with straps and screws at this point. Each of the bulkheads were constructed in earlier chapters. The fuselage sides were also constructed earlier using a hand made wooden forms. Now, it is all coming together in a trial fit.
Tiki Broker, Here Tiki, Tiki, Tiki
(If you click (above) on my neighbor across the street, "Big Ed," you will find yourself in an online Polynesian oasis complete with mood music where the Tiki Broker can sell you Tiki idols to decorate your hangar in style. Tell him Dan sent you.)

Fuselage , front side, upside down, during assembly with epoxy and flox. Clamps, straps, and bungee cords were used in addition to pipe clamps available at woodworking stores.
.Cozy Mark IV fuselage clamped during assembly

Adding fiberglass BID tapes using the aluminum foil method.
Applying fiberglass BID tapes to the seatback of the Cozy Mark IV

Fuselage assembly. In front of the airplane are the BID tapes that I have made with aluminum foil, two layers of BID fiberglass, epoxy, and 4 mil plastic (tutorial on this technique is available here). After the sandwich is made and the glass is wet, I cut the fiberglass into strips 2" wide. In the foreground is my rolling podium. My aircraft construction plans, notes, and other things are always on the podium and handy in my work area. If you are familiar with this kind of airplane, this photo may look funny. That is because the plane is upside-down on the table here because I assembled it using a different method than the plans spell out.
Cozy Mark IV fuselage photo (inverted)


Cozy Mark IV N57DD (reserved) gets finally turned right side up, additional glass reinforcements are performed on the landing gearbulkheads (forward face, forward bulkhead) and the F22 Bulkhead, and areas are sanded and cleaned that were not easily visible before and then the F28 bulkhead gets installed 6.25 inches aft of F22 (fwd face) as corrected in the FAQ.

The additional glass reinforcements described above, and in the third photo (below) are fully described in a tutorial that I have written here.

I have not drilled the large holes in the landing gear bulkheads yet (2nd photo below). I delayed drilling the holes while I was doing Chapter 4.

Cozy Mark IV Fuselage photo Cozy Mark IV, Chapter 6, Landing Gear Bulkhead 3-ply UNI layup Cozy Mark IV F22 Bulkhead BID reinforcement layup Cozy Mark IV, F28 Bulkhead installation


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Copyright (C) 2008, 2009 - Daniel Dillon - All rights reserved.